Problem 7 - Biology of Humans: Concepts, Applications, and Issues

Question

Choose the correct statement: a. Cartilage rings keep the alveoli open. b. The temperature and humidity of the air are adjusted as the air flows through the nasal cavities. c. The larynx changes shape as we speak, creating resonance chambers of different sizes. d. The center of each lung contains a large hollow area in which most of the gas exchange occurs.

Step-by-Step Solution

Answer

The correct statement is b.

Step 1: Identify the Incorrect Statements

First, evaluate each option to identify whether it is true or false. Option a: Cartilage rings keep the trachea open, not the alveoli. Option d: The gas exchange occurs in the alveoli, not a large hollow area in the center of each lung.

Step 2: Confirm the Correct Statement

Option b: The nasal cavities adjust the temperature and humidity of the air as it flows through. This statement is correct based on human anatomy and physiology. Option c: The larynx does change shape as we speak, but it is primarily responsible for sound production, while resonance chambers are formed by surrounding structures, such as the pharynx, mouth, and nasal cavities.

Step 3: Final Selection

Considering the analysis, the correct statement is that the temperature and humidity of the air are adjusted as the air flows through the nasal cavities.

Key Concepts

nasal cavities

The nasal cavities are a crucial part of the human respiratory system. They have multiple functions that help us breathe more efficiently and protect our respiratory tract. Firstly, as air enters through the nostrils, the nasal cavities help to adjust its temperature. Warm blood vessels close to the surface heat the air. This prevents cold air from shocking the system. Secondly, the nasal cavities humidify the air. This means that dry air is moisturized, which is important for keeping the respiratory tract moist and healthy. Lastly, the nasal cavities filter out particles such as dust and pathogens. Tiny hairs called cilia and a thin layer of mucus trap these particles.

• Warm air to suitable body temperature
• Moisturize dry air
• Filter out harmful particles

These functions make sure that the air is clean, warm, and moist before reaching the lungs.

gas exchange

Gas exchange is the process by which oxygen is taken into the body and carbon dioxide is expelled. This crucial function happens in the alveoli, tiny sac-like structures in the lungs.
When you inhale, oxygen-rich air reaches these alveoli. Each alveolus is surrounded by a network of capillaries. Oxygen passes through the thin walls of the alveoli into the blood. Simultaneously, carbon dioxide, a waste product, passes from the blood into the alveoli. This carbon dioxide is then exhaled out of the body.

• Oxygen diffuses into the blood
• Carbon dioxide diffuses out of the blood
• This efficient process ensures the body gets the oxygen it needs

The design of the alveoli, with their large surface area, optimizes gas exchange. It is a vital process that keeps our cells functioning.

cartilage rings

Cartilage rings are found in the trachea, the tube that connects the larynx to the lungs. These C-shaped rings are composed of tough, flexible cartilage tissue. Their primary function is to keep the trachea open at all times, ensuring that air can pass freely to and from the lungs.
Without these cartilage rings, the trachea could collapse, especially during inhalation when the pressure inside the trachea decreases. This would obstruct the airway and make breathing difficult.

• Located in the trachea
• Keep the airway open
• Prevent the trachea from collapsing

The C-shape of the rings also allows some flexibility and movement, which is crucial for the function of the respiratory system.